1. Field of Invention.
The present invention relates to power saws used for any metal cutting application. More particularly, the field of the invention involves such power saws used for cutting metal objects such as railroad rails used in railroad joints.
2. Description of the Related Art
In general, metal objects such as railroad rails, engine blocks, and stainless steel rods are cut for several purposes including forming railroad joints and material testing. These types of metals are conventionally cut by power saws. Conventional power saws include a saw blade that is driven by a belt coupled to a relatively high horsepower motor. The saw blade is advanced downwardly at a constant rate toward the piece of metal by a hydraulic cylinder or the like. Another feature of conventional power saws used to cut metal is an oscillating device which provides the saw blade with an oscillatory motion as it advances through the metal object. The saw blade follows a circular path as it cuts through the metal.
Power saws lacking an oscillating device maintain the blade in constant contact with the metal being cut. The temperature of the metal article at the point of contact thus elevates becoming too hot and alters the integrity of the metal. Further, due to the high temperatures, the saw blade tends to cut towards the hotter areas of the metal as it is being forced through the object. The resulting cut surface of the metal then has ridges and is not substantially flat which prevent uniform contact of the cut surfaces of two adjacent railroad rails in a railroad joint for example. The life of the saw blade is reduced in this type of power saw because of the stress applied to the blade from the force of the blade in constant contact with the metal being cut. Power saws having oscillating devices dissipate the heat created by the cutting operation so that the integrity of the metal does not change. However, the oscillatory motion of the saw blade is not controlled in a smooth, continuous motion which prevents dissipation of the heat created during cutting, thereby allowing the integrity of the metal to change. Once this occurs, the horsepower requirements necessary to force the saw through the remainder of the piece of metal being cut as well as the stress applied to the saw blade increase drastically.
Conventional power saws for cutting metal objects lack control of the vibrations created during the cutting operation. Such conventional saws lack speed desired for the cutting operation. Further, conventional power saws require frequent replacement of the saw blade.